Concrete mixer



Nov. 29, 1927. 1,650,592

A. BICKEL coucmsw MIXER Filed July 17, 1922 2 Sheets-sheet 1 jE 'a/reI,

Nov. 29, 1927. 1,650,592

- A. BICKEL coucamn MIXER Filed July 1922 2 Sheets-Sheet 2 i3 'ckel, Z/rfzzess: L

Patented Nov. 29, 1927.

UNITED STATES ACKERT BICKEL, OF KANSAS CITY, MISSOURI.

CONCRETE MIXER.

Application filed July 17,

The present invention relates to mixing apparatus and aims to provide an improved mixer construction characterized by a novel and efficient means for effecting both the agitating of the material in the mixing operation and also the discharge of each bath of material from the ,mixing chamber.

For this purpose, I have devised a mixing recaptacle provided with agitating means or bla es cooperating in the rotative movement of the receptacle for carrying out the mixing operation, and thereafter operating while the receptacle is maintained stationary to effect the discharge Qftllfi contents from the receptacle.

It is also sought to improve generally this type of machine, by providing a more efficient construction and improved operation, and an increased capacity for each apparatus, while maintaining the cost of manufacture of the machine at practically a minimum.

With these general objects in view, the invention will now be described by reference to accompanying drawings illustrating one form of apparatus which I have devised for embodying the improvements proposed, after which those features deemed to be novel will be particularly set forth in the claims In the drawings Figure 1 is a central vertical sectional view of a mixing apparatus constructed in ac.- cordance with the present invention;

Figure 2 is a transverse section, taken on the line IIII of Figure 1;

gigure 3 is an end view of the machine; an

Figure 4 is a plan view of the same, on a reduced scale.

Referring now to the said drawings in detail, these illustrate the apparatus as com? prising a mixing drum 5 provided with journals 6 mounted in bearings 7 on standards 8 supported on any suitable framework, such as transverse channels 9 forming part of a framework adapted to be carried by the chassis 10 of a truck used for transporting the mixer. The journals 6 also provide bearings for a shaft 12 which is thus mounted coaxially with reference to the drum, and is adapted to be rotated by means of a sprocket wheel 14 or the like, slidably keyed to said shaft and actuated by a drive chain 15. The sprocket wheel is adapted to b6 1922. Serial No. 575,515.

shifted in any well known manner, by means of a shift lever 16, for the purpose of effecting clutching or unclutching engagement of pins 17 with recesses 18 in the outer ends of the journals 6 (see Figure 1), thereby connecting or disconnecting the drive from the shaft 12 to the drum-5. By this means the shaft 12 can be rotated independently of the drum 5, at which times the latter is maintained stationary by the action. of a suitable brake 20 mounted on-one of the frame pieces 9 and adapted to be operated manually into frictional engagement with the periphery ofthe drum. At one end, the drum is formed with an opening 22, having one edge flush with the drums periphery, and adapted to be maintained closed during the mixing operation by a hinged door 23 provided with latch elements 24.

Inside the drum, a plurality of arms 25 are secured to the shaft 12 by means of split clamping elements 26, the.arrangement of said arms being such as to form a series extending in a spiral or helical direction about the axis of said shaft. The outer ends of the arms 25 are equipped with materialengaging and lifting blades 27 occupying positions at an angle to the shaft (see Figures 1 and 2) and forming in effect what may be termed a sectional helical conveyor with the sections thereof overlapping and at the same time affording sufiicient clearance for the material to work its way between the sections or blades and preventing any clogging action of the parts. Adjacent each end of the drum, a scraper arm 28 is secured to the shaft 12 in position to effect scraping engagement with the end walls of the drum compartment, and thus intermittently removing the material adhering thereto.

-In operation, the drive to the drum 5 is disconnected by unclutching the spr'ocket 14 and brought to a standstill by the application of the brake 20, being stopped in such a position as to bring the opening 22 above the shaft 12 to allow a batch of the material to be fed into the drum or mixing compartment." The opening is then closed by means of the door 23, and the brake released and the sprocket 14 clutched with the adjacent journal 6 to restore the drive to the drum. The drum 5 and arms 25 with their blades 27 now rotate in unison about the axis of the shaft, in which operation it will be apparent that the arms and blades exert a continuous agitating and mixing action upon the batch of material, due to said arms and blades alternately sweeping through the material as they pass beneath the shaft and then lifting and releasing the material as they pass through the are above the shaft. As above indicated, the broken helical arrangement of this a itating and mixing structureaffords su cient clearance for the described movement of the arms and blades to avoid any clogging or choking action in the mixing operation, the scraper arms 28 further cooperating to keep any of the material from collecting on the end walls of-the mixer. At the end of the usual period allowed for the mixing operation, the sprocket wheel is unclutched from the adjacent journal 6 to disconnect the drive to the drum, and the latter brought to a stand-still by means of the brake, and with the opening 22 in the position shown in Figures 1 and 3, to allow the discharge of the material. l'Vhile the drum is maintained stationary and the .door 23 unlatched to allow the same to be swung open, the rotation of the shaft 12 is continued, with the result that the conveyor or impeller action of the blades 27 operates to feed the material in the direction of said opening 22 until substantially the entire contents of the drum are expelled from the mixing compartment. The continued operation is then simply a repetition of the foregoing. It is thus apparent that the described construction constitutes an extremely simple and yet entirely eflicient andeconomical apparatus for this'class of work. It is very evident that the method of mixing herein described, involving the movement of the mixing blades operating in unison with the drum about the same axis during the mixing operation, can be carried out with far less power effort than any operation requiring a screw-like agitating and mixing action produced within a stationary mixing drum, which would have the effect principally of packing the material in one end of the mixing chamber. This is an immense feature of advantage in connection with mixers transported on trucks and designed to carry out the mixing operation while the truck is in transit and with power derived from the same motor as is usedto drive the truck. Another chief advantage is the gain in capacity over the common type of mixer provided with a central, axial opening and operating with a batch which can not of course exceed half the volume of-the mixing chamber, whereas in the present construction the design permits the mixing chamber to be charged to at least a level with the margin of the opening 22 when the latter is located in receiving position or above the shaft 12, thus charging the mixer more than half full. A further features of advantage is the fact that the mixing operation is carried 'out with the mixer opening 23 closed, which is important in connection with mixing in transit, since there is no opportunity for losing any of the contents from the mixer due to the swash of the material, this loss of material bein one of the disadvantages characterizing al of the common types of mixers provided with the central or axial opening and having no provision for closing the same during the mixing process.

WVhile I have illustrated and described what I now regard as the preferred form of tinuously in one direction toward said outs.

let, means for rotating said receptacle and material-engaging means in unison for effecting the mixing operation, and means for maintaining said receptacle stationary and effecting the discharge of the material through said outlet by the continued operation of said material-engaging means.

2. A mixing apparatus comprising a rotating receptacle having an opening for receiving and discharging the material, a plurality of arms carrying blades arranged helically about the axis of the receptacle, said blades being progressively inclined with reference to said axis at angles adapted to impel the material, by the joint action of said blades, continuousl in the direction of said opening, means or rotating said receptacle and 'arms in unison 'about said axis, and means for maintaining said receptacle stationar and effecting the discharge of the materia through said opening by the continued rotation of'said arms.

In witness whereof I hereunto ailix my signature.

ACKER BICKEL. 

